New Health Study Finds Airport Scanners Safe

A new health study released yesterday by University of California researchers shows the radiation emitted from the controversial full-body airport scanners does not pose a significant health threat to air travelers, researchers say.

"The doses delivered by the airport backscatter scanners is truly very low, and individuals should not fear going through the scanners based on exposure to the radiation," study co-author Dr. Rebecca Smith-Bindman, a professor of radiology at the University of California, San Francisco, tells HealthDay News.

Other scientists, however, have expressed concern full-body airport scanners do pose a cancer risk. Dr. David Brenner, chief of the center for radiological research at New York's Columbia University, says the risk of radiation has been "underestimated." Brenner claims that while an individual's risk is "very low," there is statistically a cause for concern due to the large number of travelers undergoing scans.

"If all 800 million people who use airports every year were screened with X-rays then the very small individual risk multiplied by the large number of screened people might imply a potential public health or societal risk," Brenner tells Australia's Herald Sun. "The population risk has the potential to be significant."

According to the new research, passengers would need to pass through full-body airport scanners 50 times to receive the same amount of radiation delivered by a dental X-ray. It would take 1,000 scans to obtain the dose delivered by a chest X-ray, or 4,000 body scans to achieve the same radiation dose from one mammogram, the study demonstrates.

Smith-Bindman and study co-author Pratik Mehta, of the University of California, Berkeley, say the image revealed by backscatter scanners actually come from radiation reflected off the body. In contrast, medical imaging machines transmit radiation through the body.

The Transportation Security Administration now operates over 450 scanners at 78 airports throughout the U.S., a number that is supposed to more than double by the end of the year.

For the study, published in the Archives of Internal Medicine, Smith-Bindman and Mehta looked at three groups: all fliers, frequent fliers (meaning those who fly 60 or more hours a week) and 5-year-old girls who fly weekly, because children are more sensitive to radiation.

The team assumed all passengers would undergo full body scan on each trip, with 100 million passengers taking 750 million flights in a year. Among passengers on all these flights, the researchers estimated that six cancers could develop over a lifetime from scanner radiation. But according to the researchers, some 40 million cancers would result from other causes on the same fliers.

As for the most at-risk group, the hypothetical 5-year-old girls making one-round trip a week, airport scanners might cause one additional breast cancer over their lifetimes, but 250,000 breast cancers would result from other causes in this group, according to the researchers.

"Based on what is known about the scanners, passengers should not fear going through the scans for health reasons, as the risks are truly trivial. If individuals feel vulnerable and are worried about the radiation emitted by the scans, they might reconsider flying altogether since most of the small, but real, radiation risk they will receive will come from the flight and not from the exceedingly small exposures from the scans," write Smith-Bindman and Mehta in their report.